— President Obama called Thursday for new and faster construction of the nation’s petroleum pipelines, delivering a message of reassurance here in deep-red Oklahoma that the oil industry has a key role in his energy plan.

Underpinning his message was a largely symbolic call for federal agencies to speed up the review of the Keystone XL pipeline’s southern leg, which begins near here on the windy plains of Oklahoma on its way to refineries on the Gulf Coast.

“Today, we’re making this new pipeline from Cushing to the gulf a priority,” Obama told a small audience gathered in a pipe yard on a chilly morning. “As long as I’m president, we’re going to keep on encouraging oil development and infrastructure, and we’re going to do it in a way that protects the health and safety of the American people.”

Obama’s appearance here, framed by stacks of pipes awaiting assembly, reflects the growing concern within the administration over the effect gas prices, and by extension his energy policy, are likely to have on the November election. He has become increasingly vulnerable to Republican criticism as gas costs keep rising ahead of the summer driving season. And the issue comes at a time when, after several years of economic uncertainty, a growing number of Americans are feeling better about their financial prospects but are also deeply concerned about the money they are spending at the pump.

Seeing political opportunity, Republican presidential front-runner Mitt Romney called on Obama earlier this week to fire Interior Secretary Ken Salazar, Energy Secretary Steven Chu and Environmental Protection Agency Administrator Lisa P. Jackson, calling them the “gas hike trio.”

Although Obama has argued that boosting domestic oil production has never had an effect on gas prices, public opinion polls show that a large chunk of the electorate believes he could be doing more to reduce fuel costs.

Behind this stop of his four-state tour is the sense that Obama might not be focusing enough publicly on domestic oil production as his energy policy has emphasized alternative sources. In nearby Cushing, a hub for petroleum shipments, there is a glut of oil unable to reach the Gulf Coast because there isn’t enough pipeline.

“Anybody who suggests that we’re, somehow, we’re suppressing domestic oil production isn’t paying attention,” Obama said. “Anyone who says that just drilling more will bring gas prices down also isn’t paying attention; they’re not playing it straight. We are drilling more. We are producing more. But the fact is, producing more oil at home isn’t enough by itself to bring gas prices down overnight.”

Obama has little jurisdiction over the southern leg of the Keystone XL; his authority is over the proposed northern section that would cross the U.S.-Canadian border. But his January decision to reject a Canadian company’s application to build and operate the 1,700-mile pipeline has drawn fresh criticism from Republicans, who say it would create 20,000 U.S. jobs. Obama has accused them of forcing his hand by setting a deadline for his decision.

He pleased his environmental allies by rejecting it — and then angered them Thursday by endorsing the southern leg.

In a statement, Gene Karpinski, president of the League of Conservation Voters, said the “ill-advised” event here “stands in stark contrast to many of President Obama’s laudatory efforts to reduce our dangerous dependence on oil.”

“Rather than rushing efforts to transport toxic oil across America’s heartland, we should focus on putting America back in control of our energy future — creating new clean energy jobs, reducing our dependence on oil and curbing harmful global warming pollution,” Karpinksi said.

As part of his trip to promote his “all of the above” energy plan, Obama on Wednesday reiterated his demand that Congress cut off the estimated $4 billion a year in federal subsidies for oil companies. While visiting a solar power plant in swing-state Nevada and federal oil fields in New Mexico, another state in play for November, Obama argued that the subsidy money would be better spent developing alternative energy sources that would reduce the country’s reliance on oil from the volatile Middle East.

Obama was not so direct about alternative energy on Thursday in a state comfortably in the Republican column.

“If we’re going to end our dependence on foreign oil, if we’re going to bring gas prices down once and for all, instead of playing politics with it every single year, then we are going to have to develop every single source of American energy, and every new technology that can help us use it more efficiently,” he said. “That’s where we need to go.”

Republicans have cast Obama’s visit here as a political play by the president to head off backlash from the Keystone XL decision. Officials from TransCanada, the company behind the project, have said that Obama’s call for a faster review would not alter the timeline.

The southern leg of the project is awaiting final permits from the U.S. Army Corps of Engineers, and the company plans to break ground on it as early as June. Republicans have said Obama should focus on the project’s other stages, where the administration will be decisive.

In Washington on Thursday, House Speaker John A. Boehner (R-Ohio) faulted Obama for taking credit for construction of the southern leg of the pipeline, noting that the president’s approval wasn’t needed.

“He claims that he wants to address rising gas prices, but his policies are actually making matters worse for families and small businesses,” Boehner said. He later added, “There’s only one permit that requires his approval, because it crosses our national boundaries, and that’s the Keystone decision on the upper half” of the project that extends into Canada.

To conclude his trip, Obama headed to the Center for Automotive Research at the Ohio State University in Columbus, a laboratory for hybrid engines, next-generation electric cars and motorcycles, and other innovations.

Each stop on Obama’s hop-scotching energy tour was picked to illustrate an element of his policy, and the one in Columbus highlighted fuel efficiency.

But it was also the stop that felt most like a campaign rally – with hecklers, chants of “Four More Years” echoing around the cavernous room, and the president spelling out “OSU” with his arms in a nod to the school’s men’s basketball team, which plays a Round of 16 game Thursday evening in the tournament.

It was unclear what the first heckler wanted, other than for Obama to read a book the man was shouting about. The president said he would if he would stop interrupting. The crowd roared in approval. A little later, a small group of students shouted, “Stop the pipeline,” in reference to the Keystone XL project. Obama just continued speaking.

After he toured the research center, Obama told the audience of students, professors, administrators and others that “that gas spike feels like a tax hike coming right out of your pocket.” He said the payroll tax cut that he pushed and that Congress approved earlier this year will help offset those costs but that a long-range strategy to protect consumers from oil price fluctuations is essential.

He chided “politicians dusting off their three-point plans for $2 gas, only this year it’s $2.50” – the price that GOP primary candidate Newt Gingrich has said is possible under his own energy plan. And Obama warned that “there will always be cynics and naysayers who just want to keep on doing things the same way that we’ve always done them.”

Obama, his suit coat off, also urged the crowd to speak out against federal subsidies for oil companies, imploring them to call, write or e-mail their member of Congress “to let them know where you stand.”

“I need all of you to make your voices heard,” Obama said. “Tell them to do the right thing. Tell them we can win this fight. Tell them: Yes, we can. We can build an economy that lasts.”

Staff writer Ed O’Keefe contributed to this report.